Research suggests that availability of and access to family planning clinics and services (FPCs) may reduce adolescents' risk for early sexual intercourse and increase the likelihood of effective contraceptive use. However, most of these studies have relied on crude (i.e., county level) measures of FPC availability and access, which do not adequately capture spatial relationships between adolescents' place of residence and FPC locations (e.g., an adolescent who lives across the street from an FPC may be treated the same as one who lives 15 miles away). The proposed study will help fill this research gap by examining the relationship between availability and access to FPCs using physical (miles to) and temporal (time to) distance and density measures as more precise and sensitive measures of the spatial relationship between adolescents' place of residence and FPC locations. In addition, the proposed study will examine both direct and indirect effects, specifically, whether and to what degree sexual expectancies, perceived peer attitudes and behaviors, parental attitudes and parental communication, mediate the relationship between FPCs and adolescent sexual behavior. This study will also consider the possible moderating effects of age, gender, SES, and sexual experience, as well as control for important background variables. This study will utilize data from a longitudinal NICHD-funded study on adolescent sexual behavior with data on a range of adolescent sexual behaviors (oral sex, vaginal intercourse, and anal sex), contraceptive use, pregnancy, sexually transmitted infections, and psychosocial predictors. The proposed study will supplement the existing data set with geospatial coordinates of publicly-funded FPCs in California. Longitudinal data will also be used to determine whether FPC availability affects changes in adolescent sexual behavior and hypothesized mediators. Identifying effective strategies to reduce risky adolescent sexual behavior and related negative outcomes remains a public health research priority. Results of this study may have significant implications for both public policy and public health. For example, if access and availability to family planning clinics have an identifiable effect on adolescent sexual behaviors and subsequent outcomes, community leaders and city planners could use this information to better identify served and underserved areas and populations and plan future clinic development and services accordingly. Identifying effective strategies to reduce risky adolescent sexual behavior and related negative outcomes remains a public health research priority. Results of this study may have significant implications for both public policy and public health. For example, if access and availability to family planning clinics have an identifiable effect on adolescent sexual behaviors and subsequent outcomes, community leaders and city planners could use this information to better identify served and underserved areas and populations and plan future clinic development and services accordingly. [unreadable] [unreadable] [unreadable] [unreadable] [unreadable]